The present invention relates to an implantable prosthetic device and, more particularly, to biomechanical heart valve prosthesis and to a method for making a biomechanical heart valve prosthesis.
It is well known to utilize mechanical heart valves and natural tissue cardiac valves to replace defective aortic and mitral valves in human patients. The decision to utilize a mechanical heart valve versus a natural tissue product often is made at the discretion of the surgeon based on personal preferences.
Common types of mechanical heart valves include ball check valves and valves having one or more moveable lens-shaped discs. The discs may be supported in cages for axial or pivotal movement within a frame structure. The mechanical valves usually are formed of titanium and/or pyrolytic carbon materials. A fabric sewing ring, such as formed of polymer or textile material, surrounds the annular frame to facilitate its implantation.
One type of natural tissue heart valve typically employs a porcine valve for implantation in a human, as they are very similar to human valves of appropriate size and generally are easy to procure. Prior art teaches the concept of removing an aortic heart valve from a pig, treating it with an appropriate fixation solution, which may include a glutaraldehyde solution, and mounting the valve into a stent.
A stent typically is formed of a resilient material, such as a plastic (e.g., DELRIN). Examples of various stent structures are disclosed in U.S. Pat. No. 3,983,581, U.S. Pat. No. 4,035,849. The stent usually is covered with a fabric material, such as DACRON, PTFE, or other suitable textile material. The fabric material provides structure for securing the valve relative to the stent. The stented heart valve prosthesis may be implanted into a patient for a heart valve replacement.
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is intended to neither identify key or critical elements of the invention nor delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
The present invention relates to a system and method for providing a biomechanical heart valve prosthesis, which includes biological tissue, such as pericardium or collagen, associated with a mechanical heart valve. According to one aspect of the present invention the heart valve prosthesis includes a mechanical heart valve having a generally annular support and a valve member that permits substantially unidirectional flow of blood through the heart valve. For example, the mechanical valve could be a ball check valve or other valve configuration, such as having one or more moveable discs. One or more sheets of a biocompatible biological tissue material are disposed around the annular support to define at least part of a sewing ring.
In accordance with a particular aspect, the mechanical heart valve may include a fabric sewing ring. The biological tissue material thus may be applied to cover the exposed fabric material.
Another aspect of the present invention provides a method of making a heart valve prosthesis. The method includes providing a mechanical heart valve that is operative to permit substantially unidirectional flow of blood through the mechanical valve. One or more sheets of a biocompatible biological tissue material are applied around an exterior portion of the mechanical heart valve to provide a sewing ring that includes the biological tissue material. If the mechanical heart valve includes a fabric sewing ring, the biological tissue material is applied so as to cover the exposed fabric.
To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.